I am presently working on another new item that will be debuted at this years DECFEST. [smiley=icqlite20.png]

It's a portable battery operated headphone amp that I've been working on all summer. Don't know what the price will be yet, and more info will be forthcoming as it becomes available. I am frankly thrilled with the sound and ergonomics of it at this point - so my reason for posting this teaser is just as a heads up. If you're planning on buying one of these things in the near future, you may want to wait and hear this one. I have purchased a hand full of these to hear how they sound and while some were pretty good, I didn't really like any of them. I have plugged my sons IPOD into this one and listened to the MP3's he downloaded off the internet and was shocked to find for the first time ever that I could now stand to listen to MP3's and even more shocked at how enjoyable they actually were on this rig. Of course listening to a good CD is even better.

No the watch will not be included... I put it there to give you a size reference.

MINE!!! This is sweet! Is it tube powered? I suppose I could assume it is but I thought I'd ask to be sure. What's the estimated battery life? What kind of batteries does it use? Does it have a DC input as well for home use? This excites me!

Jason - It is not tube powered but I have taken great pains to voice it to sound more like tubes than solid state.

Terry - It is using Burr Brown Op amps, specifically the OPA2132 and it uses a pair of them. They are socketed so it is possible to try a few others. I prefer the FET input of these and the warm relaxed signature. Unlike common FET op amps these are free from phase inversion and overload problems during high output. The particular ones I chose are $18.00 each putting them near the top of the list for expensive Op amps... but then when you want things to sound good... ;)

Jason - It will drive headphones between 12 ohms and 600 ohms without issues. It will also maintain the same frequency balance meaning that certain impedances won't sound overly heavy while others sound overly thin. In addition long cables can be used without problems. As you probably know the longer cables introduce higher capacitance and that typically has side effects but not with the ZenPod.

Jason - It uses a single 9 volt battery that can be accessed without having to unscrew stuff giving it an ergonomic advantage over all it's competition. Battery life is around 40 to 50 hours. I have provisions for a DC adapter but not sure if I will implement it or not. Without getting long winded here, the sound quality pales in comparison to the battery. Also, good old cheap alkaline batteries sound better then rechargeable ones. The natural progression would be to have the unit charge itself while the DC adapter is used so many people would do that at the expense of sound quality. This is another way the ZenPod outclasses its competition in my view. It is an audiophile product, not a bells and whistles item.

60 - I'm not going to say that can't happen, but I've been walking around with it in my shirt pocket for a week now and it's not happened yet. Also the volume is a smooth increase, not super touchy so that helps. You can put any 6 mm knob on it though, so if it were a problem for someone its a problem that could probably be overcome.

Had the same experience. The reasons are probably many, but in my experience the MAIN key is cross-feed. There seems to be at least a million wrong ways to implement cross-feed including not having it. A lot of these portable headphone amps are grossly over complicated... you know, press the button and hold for 3 seconds to turn it on for 3 hours, press twice to turn it into a flashlight... surface mount circuits with processors and DSP attempts at adjustable cross feeds, selectable gain levels, selectable impedance settings. Christ I just want it to work... woops got off on a bit of a tangent there.

The cross feed is the key, and it must be done correctly. The lack of cross feed in most headphone devices is why most people learn to hate headphones. Can't blame them either. Nothing worse then a total lack of imaging combined with super wide stereo effect that makes it sound like the music is playing inside your head. The cross feed circuit I use is the only one that to my ears works correctly and sounds natural. And no I didn't invent it, just smart enough to try everything published and recognize what worked once I heard it. I still have to write the paper on it and probably should before I start selling these things.

You know when you've been listening to a good set of headphones on your head for 3 or 4 hours and literally have to force yourself to pry them off ... that's good sound. This is happening even with MP3's on an IPod! The cross feed was the deciding factor in making this true.

Don't worry I'm going to make everyone listen to it at the DECFEST whether they want to or not. Most won't want to because they've learned to hate headphones for the reasons I mentioned above. They will likely be pleasantly surprised. First of all, headphones are never better then what drives them. When done correctly they smoke even my best stereo gear in the listening room in so many ways. It is a real rush with this portable to hear sound that good and then walk outside and work in the yard while listening because something inside you says this should be impossible.

The cross feed is the key, and it must be done correctly. The lack of cross feed in most headphone devices is why most people learn to hate headphones. Can't blame them either. Nothing worse then a total lack of imaging combined with super wide stereo effect that makes it sound like the music is playing inside your head....Steve

How does the CSP2 handle this with its headphone output? I always wondered. Can these opamps possibly be in the same league?

If only 45v batteries were still in use. I know a collector that has a 3 tube pocket fm radio. 1.5v heaters and a 45v battery for the plates. 5 9v batteries might be a hard sell.

So Steve, is this only for 300+ ohm headphones, or can this be used with low impedence headphones as well??

Jason

My Stax "energizer" or whatever it's called is portable running on 4 "D" cells (or plugged in with a wall wart). Somehow it's able to turn the voltage from the batteries into 580 V bias for the electrostatic field, must be an extremely small curent.

How have you found using the mp3 player with the ZenPod. Do they jumble around in your pocket?

Would it be worth supplying a small velcro strip to keep the units joined together?

I listen to my I-Pod while I'm on the train or in the car and often have the unit on my lap or resting next to me. Having a method of joining the two may stop one of them being dropped or wires becoming tangled.

I wondered how long it would take for this to come about. :) Although, I've never seen an OPA2132 that cost over $8 so I'm interested to see which version it ends up being. Lots of film cap action going on? I hope there are some nice, low-impedance lytics in the power stage of that baby.

Hey, I've always been interested in getting a headphone amplifier. Of course, everyone clowns on my MDR-V700's, but anyway, I don't use a portable media player. I just listen at my PC so I have no interest in battery power, or rather not soley battery power. Are you going to have a version which I could plug into the wall and listen to at my desk? Because I listen for hours at a time while doing whatever on my PC!

P.S. Really, what sort of sound cards are you running in any of your given PC, Steve? Have you tried outputting ASIO from any of them? It's fantabulous in comparison to stock... and films help.

Unfortunately, those different likes are also what keep companies in business, especially the posers.

Are you serious in saying that people's different taste (likes) in hifi presentation is "unfortunate"? Are you therefore advocating a single way of presentation being the "right" one? Would be grateful if you can clarify what you mean.

I think the perception of "inside your head" means different things to different people. It is a poor way to describe what sound we're talking about. From the one perspective it is of course all inside your head... however taking that perspective, it becomes about the sound stage that is inside your head. The sound we typically refer to as "inside your head" is really referring to a small center image that appears exactly between your ears in a tiny singular spot. A highly unnatural experience. A very "closed in" sound might be another way to describe it, where instead we are trying to let the music open up and relax more. The point is whether you like the band playing inside your head or like to be transported to the venue could actually be the same thing. Either one demands a spacious sound with the proper ambiance to feel natural or believable not to mention non-fatiguing.

Steve

Price still pending. It was not designed to be price competitive. It was designed for the more serious audiophiles who don't want or need more inexpensive junk.

Of all the sets of headphones tested with it, the Zen Pod refused to drive mine! I asked Steve about this and he was unsure. He tested them with 10ohm and 250ohm headphones, driving both just fine. However, my 32ohm headphones clipped the output. He's looking into it. However, I don't want to make it sound like a failure, or a bad product. On Steve's 250 ohm headphones, the difference between the ipod directly and the Zen Pod was astonishing! The Ipod just didn't have the juice to drive em. Volume all the way up was acceptable, but bearly. With the Zpod, however, there was plenty of volume. The bass changed as well. It took on an effortless quality, sounding more natural and smooth with more headroom. Even on my friend's Sennheiser PX100s, the bass improved considerably. We tried close to 10 sets of headphones of varying impedences. The 32ohm Grado's were driven wonderfully.

As far as basic functionality, I suggested he change the headphone output to 1/4" for duribility reasons. The volume knob and power switch were the only other functions and both were easily accessable. The box was larger than the nano, but not huge. I believe the same battery was in the unit for the whole fest and every time I walked up to it, it was on. Steve estimated around 40hrs per battery, and it seemed very possible. Changing the battery was simple enough. The power switch was a little difficult to turn off, especially if you have large fingers. It'd probably just take some getting used to.

Thanks for your thoughts Jason. That's the great thing about Decfest: people can test out new Decware kit and Steve can get initial feed back for further development before launch. The important thing is that the Z-Pod made a significant improvement to the sound coming from a stock ipod jack on most headphones. Was there a noticeable sonic difference between crossfeed and none? Or is it an effect that should be "invisible"

Having had a few days to ponder it, I suspect these two phones are causing an oscillation.

This is a rather high fidelity unit. Had anyone listened to it on the tube output CD player vs the IPod, I think they would have been amazed. So the question becomes do we add more parts to improve compatibility at the possible risk of changing the way it sounds... or not? I'll keep working on it.

So the question becomes do we add more parts to improve compatibility at the possible risk of changing the way it sounds... or not? I'll keep working on it. I do like the idea of going to a 1/4 inch jack - for several reasons.

Thanks for the info Steve -

Any ideas why one set of headphones might oscillate and not another?

I think there is only so much you can do and compromise on to ensure compatibility. Surely that's what your money back if not satisfied guarantee is for. Personally, I'd prefer a higher quality and compromise compatibility (if that was the choice). A list of compatible headphones could then be posted on the info section of the online catalogue.

Yeah - I like the 1/4 jack if there is enough space (what about input?).

I brought the Sennheiser HD-485. I would consider them entry high end level headphones. Interestingly enough, the high end and the cheapies worked the best.

I like the 1/4 in jack as basically all mid to high end headphones come with either a 1/4 plug, or a 1/8 to 1/4 adaptor. If you're going to spend the time and money to get a product like this, you're probably buying headphones that come with said adaptors. Additionally, 1/4 in jacks are much stronger and more reliable over time.

Giorgino, I honestly wasn't listening for the crossfeed. I've become so used to my non imaging speakers and in the head sound with headphones that I simply didn't notice. That's not to say it's unnoticeable, just that I wasn't paying attention.

While I was at Decfest, the thought never occured to me to try it with the CDPlayer. ::) Oh well.

Thanks for the info morpheous85. No worries about the crossfeed/listening via CDP. You guys had such a lot of toys and distractions. . I have the Senns HD650 (good) , PX200 (ok but not special), AKG 271 (very good) and soon RS1. Hopefully, one day Stax Omegas or Senn Orpheus will be in the collection. There's a lot to be said for headphone listening with no issues of cabinet sound, room acoustics. crossovers etc. I suspect that I'll eventually move fully into headphones. It's just that darned acoustic melon effect from headphones!

Since reading Steve's thread, I've been reading up on portable headphone amps and there's a world of the stuff out there. Crossfeed and non and some with sub-miniature tubes. All fun stuff!

Has anyone tested this on a Shure SE530 (36 ohm)? So far Shure SE530 is my favorite travel phones with a MP3 player. I am really interested in buying something like this ZenPod, but I want to make sure it will work with my headphones (AKG K 701 seems to be already crossed out from the list. I also have Grado SR-60 and Grado SR-80. If those were tested as well, let me know).

I have a pair of SE530 and a Zune (has better sound than iPod), but I wanted to improve the sound of it and was looking for something like this. I tried out the HeadRoom Total BitHead and DIY CMoy pcoket amp. Neither of them which I was impressed with.

I thought about buying a CSP2 as a dedicated headphone amp for my office, using the computer/Zune as the source, but I think CSP2 does not like Shure SE530 or AKG K 701, and don't feel like forking up for a Senheiser HD650.

Has anyone tested this on a Shure SE530 (36 ohm)? So far Shure SE530 is my favorite travel phones with a MP3 player. I am really interested in buying something like this ZenPod, but I want to make sure it will work with my headphones (AKG K 701 seems to be already crossed out from the list. I also have Grado SR-60 and Grado SR-80. If those were tested as well, let me know).

I have a pair of SE530 and a Zune (has better sound than iPod), but I wanted to improve the sound of it and was looking for something like this. I tried out the HeadRoom Total BitHead and DIY CMoy pcoket amp. Neither of them which I was impressed with.

I thought about buying a CSP2 as a dedicated headphone amp for my office, using the computer/Zune as the source, but I think CSP2 does not like Shure SE530 or AKG K 701, and don't feel like forking up for a Senheiser HD650.